Fear can sometimes be a useful emotion. For instance, let's say you're an astronaut on the moon and you fear that your partner has been turned into Dracula. The next time he goes out for the moon pieces, wham!, you just slam the door behind him and blast off. He might call you on the radio and say he's not Dracula, but you just say, "Think again, bat man."

Sometimes I think you have to march right in and demand your rights,even if you don't know what your rights are, or who the person is you're talking to. Then on the way out, slam the door. - Deep Thoughts (Saturday Night Live)